WHAT IS SPRAY NOZZLE PROTECTION? Spray Nozzles are specifically engineered for four critical functions: flow control, cleaning, coverage, and atomizing. It is important to filter solids from water, or any industrial liquid, before they reach your spray nozzles.
Unwanted and oversized particles can block the inside of an orifice, which in turn restricts water flow, impairs spray uniformity, and allows debris to pass through which in turn ends up in your process or on your product.
The proper filtration will help keep the nozzle clear of debris enabling them to provide uniform and consistent spray patterns.
For spray nozzle protection, careful media selection is essential. The primary factor to be considered is orifice size and shape of the nozzle opening. Other factors include solids content, type of contaminant, particle size, and shape, amount of contaminant to be removed, liquid temperature, and required flow rates.
For liquids other than water, knowing the liquid’s viscosity, corrosiveness, abrasiveness, and adhesive qualities are essential in specifying the nozzle protection filter.
EXAMPLE — FLUE GAS SCRUBBER SPRAY NOZZLE PROTECTION
To prevent fly ash and sulfur dioxide from venting into the atmosphere, flue gas scrubbers uniformly spray a sorbent into the dirty, hot flue gas. These sorbents, however, often contain oversized particles that can plug spray nozzle orifices. When this happens, the spray becomes uneven, and fly ash and sulfur dioxide can escape from the scrubber.
The key to spray nozzle protection is to filter the liquid before sending it to the spray nozzle. This eliminates the excess and oversize particles, which ultimately plugs the nozzle orifices. Once plugged, the spray becomes uneven, and the output quality becomes compromised. All at an additional and unnecessary expense to the bottom line.
The pro-active approach to this problem is to protect the spray nozzles, which is to filter the solution before it reaches this stage of the process. While there are many different filtration options, the most cost effective is to use self-cleaning filters. This is why incinerator systems manufacturers regularly contact Eaton to analyze their filtration methods in hopes of protecting their expensive spray nozzles while lowering their process costs.
A SELF-CLEANING SOLUTION
Eaton typically determines that the solution to this problem is twofold. To begin, many manufacturing facilities are throwing out more cartridges than necessary with disposable media. That is because disposable media are typically changed on a time cycle (e.g., once a shift, once a day, or once a week), regardless of whether the media needs replacement. To effectively filter when needed — and not when convenient — it is important to use automation when at all possible.
With the use of automation, the filters can be cleaned at precisely the right time, rather than when it is convenient. That is because the cleaning is controlled by the pressure differential between inlet and outlet headers as contaminants build up on the filter screen. When the pressure reaches a predetermined level, the screens are cleaned automatically — only as needed, and when needed.
The second problem was their use of processing liquids (sorbent) with unwanted and prior supposedly ‘filtered’ particles in it, which resulted in fouling and clogging of the spray nozzles. The consequence of this dynamic was uneven spray and fly ash/sulfur dioxide escaping from the scrubber.
Once identified, the incinerator systems manufacturer eliminated this problem by using Eaton self-cleaning filters. This meant less waste in the process. It also limited the unwanted particles in the process stream, which eliminated the spray nozzle clogging. Therefore, the process line did not have to be stopped to clean the nozzles.
The incinerator systems manufacturers are extremely pleased with the reliable operation of the filters, the elimination of spray nozzle plugging and fouling, as well as the fact that there are no spent cartridges to dispose.
–by Ask Filter Man
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